Head-up display device

Abstract

A head-up display device (1) comprises a housing (10) and a display unit (20). The housing (10) has an opening (11) facing a windshield (WS), and the display unit (20) is mounted therein. The display unit (20) comprises a display (21), a reflection mirror (22), and a transparent cover (23). The display (21) is housed in the housing (10) and emits display light (L1). The reflection mirror (22) is housed in the housing (10) and reflects magnified display light (L2), obtained by magnifying the display light (L1) emitted from the display (21), toward the windshield (WS) through the opening (11). The transparent cover (23) is a cover that closes the opening (11) and transmits light, and includes a free-form surface (232a) that performs aberration correction on the enlarged display light (L2) reflected by the reflection mirror (22).

Description

Area

[0001] The present invention relates to a head-up display device background

[0002] Conventionally, for example, Patent Literature 1 describes, as a head-up display device, a vehicle head-up display that displays a virtual image via a windshield of a vehicle. The vehicle head-up display includes a case disposed on an instrument panel of a vehicle and having an opening through which image light of an image is irradiated, a display housed in the case and irradiating the image light of the image, a magnifying glass housed in the case and magnifying and reflecting an image directly incident from the display, and a lens that closes the opening of the case and magnifies the image incident from the magnifying glass to output the image to a windshield. Citation listPatent literature

[0003] Patent Literature 1: JP 2006-91104 A SummaryTechnical task

[0004] For example, in the vehicle head-up display described in Patent Literature 1 described above, when a larger virtual image is displayed, it is difficult to correct aberration of the virtual image only with a magnifying glass, and there is room for improvement in this regard.

[0005] The present invention has been made in view of the foregoing, and an object of the present invention is to provide a head-up display device that can appropriately display a virtual image. Solution to the task

[0006] The head-up display device according to the present invention comprises: a display unit provided in a vehicle and displaying a virtual image by reflecting display light radiated toward a light-transmitting reflective member toward an eye point by the reflective member;and a housing having an opening facing the reflective element and in which the display unit is mounted, wherein the display unit includes a display housed in the housing and emitting the display light, a reflection mirror housed in the housing and reflecting magnified display light obtained by magnifying the display light emitted from the display toward the reflective element through the opening, and a transparent cover closing the opening and transmitting light, wherein the transparent cover has a free-form surface that performs aberration correction on the magnified display light reflected by the reflection mirror. Advantageous effects of the invention

[0007] The head-up display device according to the present invention can correct the aberration of the virtual image caused by the optical element including the reflective element through the free-form surface of the transparent cover. The head-up display device can appropriately perform aberration correction and magnification processing of the virtual image by causing the transparent cover to primarily have the aberration correction function and causing the reflection mirror to primarily have the magnification function. As a result, the head-up display device can appropriately display the virtual image. Short description of the drawings Fig. 1 is a schematic view illustrating a configuration example of a head-up display device according to an embodiment. Fig. 2 is a perspective view illustrating a configuration example of a transparent cover according to the embodiment. Description of embodiments

[0008] A form (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the content described in the following embodiment. Furthermore, the constituent elements described below include those that can be easily understood by those skilled in the art and those that are essentially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or changes in the configuration can be made without departing from the spirit of the present invention. [Embodiments]

[0009] A head-up display device 1 according to an embodiment will be described with reference to the drawings. The head-up display device 1 is provided in a vehicle and displays a virtual image S by reflecting display light L1 radiated toward a windshield WS capable of transmitting light toward the eye point from the windshield WS. Here, the windshield WS is an example of a reflective member, is a member formed of transparent glass in a plate shape, is provided in front of the driver's seat, and blocks wind.The head-up display device 1 may be an AR-HUD device that superimposes and displays the virtual image S on an object in front of the vehicle (e.g., a person, a traffic sign, another vehicle, or the like), or it may be a HUD device that displays the virtual image S without superimposing the virtual image S on the object in front of the vehicle. The head-up display device 1 will be described in detail below.

[0010] Here, a direction along the vehicle width direction of the vehicle is referred to as a first direction X, a direction along the overall longitudinal direction of the vehicle is referred to as a second direction Y, and a direction along the vertical direction of the vehicle is referred to as a third direction Z. The second direction Y may also be referred to as a direction along a straight-exit direction in which the vehicle travels straight ahead. The third direction Z may also be referred to as a direction along the vertical direction. The first direction X, the second direction Y, and the third direction Z intersect each other and are typically perpendicular to each other. The first direction X and the second direction Y may also be referred to as directions along a horizontal plane perpendicular to the vertical direction.

[0011] As in Fig. As shown in Figure 1, the head-up display device 1 comprises a housing 10 and a display unit 20.

[0012] The housing 10 is provided in a vehicle, and the display unit 20 is mounted therein. The housing 10 is formed in a box shape and houses a display 21 and a reflection mirror 22 of the display unit 20 described later in the housing 10. The housing 10 has an opening 11 that allows the inside and outside to communicate with each other. The opening 11 is a side provided to face the windshield WS and can transmit light.

[0013] The display unit 20 displays the virtual image S by reflecting the display light L1 emitted toward the windshield WS through the windshield WS toward the eye point EP. The display unit 20 includes the display 21, the reflection mirror 22, and a transparent cover 23.

[0014] The display 21 emits the display light L1 containing an image and is housed in the housing 10. The display 21 includes, for example, a display and a backlight. The display forms an image and includes, for example, a thin-film transistor liquid crystal display (TFT-LCD) or the like. The backlight irradiates the back of the display with light and includes, for example, a plurality of light-emitting diodes (LEDs). The display 21 emits the display light L1 containing an image from the display toward the reflection mirror 22 by irradiating the display with light from the backlight. For example, the display 21 emits the display light L1 toward the reflection mirror 22 directly without using another mirror. That is, no optical component is arranged between the display 21 and the reflection mirror 22.

[0015] Note that in this example, in the display 21, a part of the display 21 is housed inside the housing 10, and the other part of the display 21 is exposed to the outside of the housing 10. Specifically, in the display 21, an emitting unit (e.g., a display) that emits the display light L1 is housed inside the housing 10, and a portion (e.g., backlight) excluding the emitting unit of the display 21 is exposed to the outside of the housing 10.

[0016] The reflecting mirror 22 completely reflects light and is housed in the housing 10. The reflecting mirror 22 has a reflecting surface 221 that has a concave shape and an aspherical shape. The reflecting surface 221 is arranged to face the display 21 and is arranged to face the transparent cover 23. The reflection mirror 22 magnifies the display light L1 (image) emitted from the display 21 with the reflection surface 221 and reflects the magnified display light L2 toward the windshield WS through the opening 11 (transparent cover 23) of the housing 10. Specifically, the reflection mirror 22 magnifies the display light L1 emitted directly from the display 21 without the aid of another mirror with the reflection surface 221 and reflects the magnified display light L2 toward the windshield WS through the opening 11 (transparent cover 23) of the housing 10.

[0017] The transparent cover 23 is a cover that closes the opening 11 of the housing 10 and allows light to pass through. The transparent cover 23 is formed of a transparent resin in a curved plate shape and closes the opening 11. The transparent cover 23 has a curved portion 230 formed in a curved shape toward the inside of a housing 2. As shown in Fig. 2, the curved portion 230 has an outer surface part 231 as a second surface part and an inner surface part 232 as a first surface part.

[0018] The outer surface part 231 is a surface part located away from the reflection mirror 22 and is formed to be curved toward the inside of the case 2. That is, the outer surface part 231 is a surface part provided close to the windshield WS. The outer surface part 231 reflects external light toward a shade portion F. Here, the shade portion F shields light and is constructed opposite to the eye point EP with respect to the opening 11. That is, the shade portion F is a wall portion provided to extend along the third direction Z, the wall portion being opposite to the eye point EP with respect to the transparent cover 23. In this example, the shade portion F is provided slightly inclined toward the transparent cover 23.The outer surface part 231 is formed in a shape that reflects external light incident from the outside of the housing 2 toward the aperture portion F. Specifically, the XZ cross-section, cut along the first direction X and the third direction Z, of the outer surface part 231 is formed linearly without being curved. The YZ cross-section, cut along the second direction Y and the third direction Z, of the outer surface part 231 is formed in a curved shape and is formed in a curved shape with a curvature that can reflect external light toward the aperture portion F. The outer surface part 231 reflects external light incident from the outside of the housing 2 toward the aperture portion F.

[0019] The inner surface part 232 is a surface part located close to the reflection mirror 22 and is formed to be curved toward the inside of the housing 2. That is, the inner surface part 232 is a surface part provided away from the windshield WS. The inner surface part 232 has a free-form surface 232a. The free-form surface 232a is a curved surface that cannot be expressed with a simple mathematical equation, such as a sphere or a cylinder. A free-form surface 232a is, for example, a curved surface in which a plurality of nodal points and a plurality of curvatures are defined in a space, and the respective nodal points are interpolated with a high-order polynomial. The free-form surface 232a is formed in a shape that corrects aberration of the virtual image S generated by the optical element, including the windshield WS and the like.The free-form surface 232a is formed in a shape that corrects an aberration of the virtual image S generated by the shape of the windshield WS, for example. The transparent cover 23 performs aberration correction on the magnified display light L2 reflected by the reflection mirror 22 through the free-form surface 232a. Then, the transparent cover 23 radiates the corrected magnified display light L2, which has undergone aberration correction with the free-form surface 232a, toward the windshield WS. The corrected magnified display light L2 radiated toward the windshield WS is reflected by the windshield WS toward the eye point EP and guided to the eye point EP.

[0020] As described above, the head-up display device 1 according to the embodiment includes the housing 10 and the display unit 20. The housing 10 has an opening 11 facing the windshield WS, and the display unit 20 is mounted therein. The display unit 20 is provided in the vehicle and displays the virtual image S by reflecting the display light L1 emitted toward the windshield WS, which can transmit light toward an eye point EP, through the windshield WS. The display unit 20 described above includes the display 21, the reflection mirror 22, and the transparent cover 23. The display 21 is housed in the housing 10 and emits the display light L1.The reflection mirror 22 is housed in the housing 10 and reflects the magnified display light L2 obtained by magnifying the display light L1 emitted from the display 21 through the opening 11 toward the windshield WS. The transparent cover 23 is a cover that closes the opening 11 and transmits light, and has the free-form surface 232a that performs aberration correction on the magnified display light L2 reflected by the reflection mirror 22.

[0021] With this configuration, the head-up display device 1 can correct the aberration of the virtual image S generated by the optical element including the windshield WS and the like with the free-form surface 232a of the transparent cover 23. The head-up display device 1 causes the transparent cover 23 to mainly have the aberration correction function and causes the reflection mirror 22 to mainly have the magnification function, so that the accuracy of the aberration correction can be improved and the magnification ratio can be improved. The head-up display device 1 can be easily manufactured because the parameter coefficients can be reduced by performing the roll distribution, thereby reducing the tolerance.In the head-up display device 1, the transparent cover 23, which closes the opening 11 of the housing 10, also has a function of correcting aberration, so that an increase in the number of components and an increase in the size of the optical system can be prevented. As a result, the head-up display device 1 can appropriately display the virtual image S.

[0022] In the head-up display device 1, the display 21 directly radiates the display light L1 toward the reflection mirror 22. The reflection mirror 22 reflects the magnified display light L2 obtained by magnifying the display light L1 directly emitted from the display 21 toward the windshield WS through the transparent cover 23. With this configuration, the display 21 in the head-up display device 1 radiates the display light L1 directly toward the reflection mirror 22 without the assistance of another mirror, so that the device can be downsized.

[0023] In the head-up display device 1, the free-form surface 232a is formed on a surface of the transparent cover 23, which surface is close to the reflection mirror 22. With this configuration, the head-up display device 1 can appropriately reflect the external light toward the aperture portion F through the outer surface part 231 of the transparent cover 23, which outer surface part is located away from the reflection mirror 22.

[0024] It should be noted that in the above description, an example has been described in which the display 21 radiates the display light L1 directly to the reflection mirror 22 without the aid of another mirror, but the present invention is not limited to this, and the display may radiate the display light L1 indirectly to the reflection mirror 22 via another mirror.

[0025] The example in which the free-form surface 232a is formed on a surface of the transparent cover 23, the surface being close to the reflection mirror 22, is described, but the free-form surface is not limited to this and may be formed on a surface of the transparent cover 23, the surface being away from the reflection mirror 22.

[0026] The transparent cover 23 may have a function of magnifying the magnified display light L2 (image) in addition to the function of correcting the aberration of the virtual image S by the free-form surface 232a. In this case, the transparent cover 23 magnifies the magnified display light L2 (image) at a magnification ratio smaller than the magnification ratio of the reflection mirror 22. For example, the transparent cover 23 magnifies the magnified display light L2 (image) at a magnification ratio of approximately 1 / 10 of the magnification ratio of the reflection mirror 22.

[0027] The reflection mirror 22 may have a function of correcting the aberration of the virtual image S in addition to the function of magnifying the display light L1 (image) through the reflection surface 221. In this case, the reflection mirror 22 corrects the aberration of the virtual image S, with the aberration correction amount being smaller than that of the transparent cover 23. For example, the reflection mirror 22 corrects the aberration of the virtual image S with an aberration correction amount of approximately 1 / 10 of the aberration correction amount of the transparent cover 23.

[0028] Although the example in which the reflecting element is the windshield WS has been described, the reflecting element is not limited thereto and may be, for example, a combiner or the like. List of reference symbols 10 housings 11 Opening 20 display unit 21 Advertisement 22 reflection mirrors 23 transparent cover 232a Freeform surface EP Eyepoint L1 Indicator light L2 enlarged indicator light S virtual image WS windshield (reflective element) QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2006-91104 A

[0003]

Claims

[1] Head-up display device, comprising: a display unit provided in a vehicle and displaying a virtual image by reflecting display light radiated toward a light-transmitting reflective member toward an eye point by the reflective member; and a housing having an opening facing the reflective element and in which the display unit is mounted, wherein the display unit includes a display which is housed in the housing and emits the display light, a reflection mirror accommodated in the housing and reflecting magnified display light obtained by magnifying the display light emitted from the display toward the reflecting element through the opening, and a transparent cover that closes the opening and transmits light, the transparent cover having a free-form surface that performs aberration correction on the magnified display light reflected by the reflection mirror. [2] The head-up display device according to claim 1, wherein the display emits the display light directly to the reflection mirror, and the reflection mirror reflects the magnified display light obtained by magnifying the display light directly emitted from the display through the transparent cover to the reflecting element. [3] The head-up display device according to claim 1 or 2, wherein the free-form surface is formed on the reflection mirror side of the transparent cover.

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